Publisher Health

University of Virginia School of Medicine researchers have identified a potential way to battle the health effects of obesity and type 2 diabetes in women after discovering an important factor that could determine how their bodies use and store fat.
Based on their new discovery, the researchers, led by Associate Professor of Biomedical Engineering Mete Civelek, PhD, were able to change whether female lab mice’s bodies stored fat subcutaneously (under the skin) or viscerally (wrapped around the organs). While visceral fat goes unseen, hidden deep inside the body, it can be particularly harmful to good health.
The researchers say their results in mice suggest that a similar approach could help treat the effects of obesity and battle metabolic diseases, such as diabetes, in women.
“There is a strong need for targeted therapies against metabolic abnormalities caused by obesity and diabetes,” said the study’s first author, Qianyi Yang, PhD, of UVA’s Center for Public Health Genomics. “We hope that increasing KLF14 abundance in fat cells of females with obesity and diabetes may provide a novel treatment option to alleviate these metabolic abnormalities.”
How We Store Fat
Men and women naturally store fat differently. Men tend to be more apple-shaped, meaning they store fat around the waist, while women tend to be more pear-shaped. This is because women store more subcutaneous fat and less visceral fat in their lower body. Civelek’s new findings help explain why.

As heavy or frequent alcohol use escalates, some people continue to drink despite increasingly negative consequences such as poor job or school performance, unraveling family or personal relationships and declining physical health.
Impaired working memory, a common problem for those with alcohol use disorder (AUD), can interfere with recovery and disease management, and contribute to the risk of relapse. Working memory is one of the processes of executive function, a set of high-level mental skills (also encompassing flexible thinking and self-control) needed to learn and to manage daily life.
“People with severe alcohol dependence have reduced ability to make sound decisions, or good choices,” said Brendan Walker, PhD, a professor of psychiatry and behavioral neurosciences at the University of South Florida Health (USF Health) Morsani College of Medicine. “They ignore the problems created by excessive drinking and give up things of importance to satisfy their craving to drink more.”
Dr. Walker studies the biological brain changes that drive addictive behaviors with the aim of finding ways to improve treatment outcomes. A major obstacle to recovery, even months or years after rehabilitation and prolonged abstinence, appears to be physical changes in neurotransmitters and their receptor targets as the brain adapts to abuse of alcohol or other drugs.
Dr. Walker’s laboratory and others have focused on the interaction of alcohol-induced “feel bad” brain peptides (neurotransmitters) known as dynorphins that bind with kappa-opioid receptors (KORs), naturally occurring receptors for opioids in brain cells.
Now, for the first time, a preclinical study led by Dr. Walker shows that dysregulated KORs in the brain’s medial prefrontal cortex region (part of the frontal lobe) contribute to working memory deficiencies in alcohol dependence. Furthermore, the researchers discovered that a compound used to block KORs (an antagonist) alleviated these working memory deficits and may help restore “normal” executive function in those with severe AUD, Dr. Walker said.

A new study in the journal Frontiers in Public Health led by scientists from the Wildlife Conservation Society (WCS) confirms that pangolins confiscated from the illegal wildlife trade in Viet Nam host SARS-CoV-2 related coronaviruses. Previously, only pangolins confiscated in China had tested positive for SARS-CoV-2 related coronaviruses.
The authors of the study say that the findings are further evidence that the transnational nature of the wildlife trade can facilitate coronavirus and other viral transmission and amplification along the trade chain, providing further evidence that pandemic and epidemic prevention must also be focused on pathogen spillover from wildlife.
The study detected SARS-CoV-2 related coronaviruses, circulating in Sunda pangolins (Manis javanica) confiscated from the illegal wildlife trade in Viet Nam. Analysis revealed that the coronaviruses identified in these pangolins were closely related to coronaviruses previously detected in pangolins confiscated from the illegal wildlife trade in Yunnan and Guangxi provinces, China.
Said the study’s lead author, Nguyen Thi Thanh Nga of WCS’s Viet Nam Program: “We know that SARS-like coronaviruses (SARS-CoV-2 and SARS-CoV-1) can cause serious disease in humans. This study confirms the presence of coronaviruses in the SARS-CoV family in trafficked pangolins in Viet Nam. Eliminating the trade in pangolins and other wild mammals and birds will eliminate this high-risk pathway for viral spillover and pathogen emergence.”
All eight species of pangolins have been listed on CITES Appendix I since 2017, prohibiting all international trade for commercial purposes. All four species of Asian pangolins, including the Sunda and Chinese pangolin (Manis pentadactyla) are considered Endangered or Critically Endangered across their geographic range.
The authors of the study tested specimens from a total of 246 pangolins from wildlife confiscation events that occurred in Viet Nam in the years 2016 to 2018. Specimens collected from seven individual pangolins in 2018 tested positive for a SARS-CoV-2 related coronavirus.
In addition to testing pangolins for SARS-CoV-2 related coronaviruses, the authors reviewed media reports of pangolin trafficking cases involving Viet Nam between 2016 and 2020. Multiple pangolin confiscation events sampled in this study in Viet Nam involved other live wildlife including a mix of non-human primates, reptiles, and birds. These observations support long-held concerns that the live wildlife trade, moving wild animals out of their natural habitats and into human dominated landscapes and large urban centers, poses a serious and increasing risk of initiating epidemics from emergent pathogens in human populations.
These findings support current recommendations on regulation of live wildlife trade and markets, including the April 2021 Interim Guidance on ‘Reducing public health risks associated with the sale of live wild animals of mammalian species in traditional food markets’ issued by the WHO, United Nations Environmental Programme (UNEP), and the International Organisation for Animal Health (OIE), which called on governments to “Suspend the trade in live caught wild animals of mammalian species for food or breeding purposes and close sections of food markets selling live caught wild animals of mammalian species as an emergency measure unless demonstrable effective regulations and adequate risk assessments are in place.”
The authors also indicate that current international recommendations are too narrowly focused on open markets and do not address the much longer wildlife supply chains, trade of both legally and illegally sourced wildlife from its source. The authors indicate the need for wildlife trade policy reform to curb the risks of future pandemics and say mitigation measures must consider that the wildlife trade spillover interface contains novel viruses, which are not detected with current sample screening practices or procedures.
Among countries, China has initiated a multi-sectoral and sustained crackdown on illegal wildlife trade and legislative reforms designed to completely phase out the farming/sourcing, trade, and consumption of terrestrial wildlife as food. Viet Nam banned the importation of wildlife in January 2020, as an immediate response to the identification of SARS-CoV-2 in China, and called for its own heightened enforcement of existing laws on illegal wildlife trade as stipulated in the July 2020 Vietnamese Government Prime Minister’s Directive No. 29 on “urgent solutions to manage wildlife.” In the past two years, the Government of Viet Nam has revised a number of decrees addressing animal health, public health, food safety, and wildlife management with the aim of mitigating the risks and impacts of future pandemics. These include Decree 14 on regulating penalties for administrative offenses involving animal husbandry and Decree 07 issued in early 2022 which increased sanctions for violating wildlife trade laws and regulations.
WCS worked closely with local partners in Viet Nam to carry out this research. We would like to thank and acknowledge the contribution of our One Health partners from the animal health sector (Department of Animal Health, Regional Animal Health Office No. 6, Dong Nai Sub-Department of Livestock Production and Animal Health, Viet Nam National University of Agriculture) and from the wildlife and environmental protection sector (Cuc Phuong National Park, Save Viet Nam’s Wildlife, Dong Nai Province Forest Protection Department). This study was carried out as part of the United States Agency for International Development (USAID) Emerging Pandemic Threats PREDICT-2 project. The URL to the USAID Emerging Pandemic Threats Program (EPT-2) is https://www.usaid.gov/ept2. More information is available on WCS one health initiatives: https://oneworldonehealth.wcs.org/ and our work on coronaviruses: https://www.wcs.org/coronavirus.
Story Source:
Materials provided by Wildlife Conservation Society. Note: Content may be edited for style and length.

Researchers at the University of Birmingham working in partnership with firms NitroPep Ltd and Pullman AC have developed new antimicrobial technology for air filters which can in seconds kill bacteria, fungi and viruses including SARS-CoV-2 — providing a potential solution to prevent the spread of airborne infections.
In a study, published today (9 March 2022) in journal Scientific Reports, the antimicrobial treatment for air filters — coated with a chemical biocide called chlorhexidine digluconate (CHDG) — were rigorously tested and compared to commonly used standard ‘control’ filters in the laboratory, in industrial air condensing units, and in a trial on-board trains operating on the UK’s railways.
In the laboratory, cells of the Wuhan strain of SARS-CoV-2 — the virus that causes COVID-19 — were added to the surface of both the treated and control filters and measured at intervals over a period of more than an hour. The results showed that, while much of the virus remained on the surface of the control filter for an hour, all SARS-CoV-2 cells were killed within 60 seconds on the treated filter. Similar results were seen in experiments testing bacteria and fungi that commonly cause illness in humans — including E. coli, S. aureus, and C. albicans — proving the novel technology to be both highly effective anti-fungal and anti-bacterial air filter treatments.
Meanwhile, in order to determine how effective the filters are in a real-world setting, both the control and treated filters were installed in heating, ventilation and air conditioning systems on train carriages. The filters were installed for three months in matched pairs across carriages on the same train-line, before being removed and shipped for analysis with researchers counting colonies of bacteria remaining on them. The trial found no pathogens survived on the treated filter, even after three months on-board the train.
Further tests also found the treated filters are durable, and are able to maintain their structure and filtration function over the lifetime of their use.
Dr Felicity de Cogan, Royal Academy of Engineering Industry Fellow at the University of Birmingham, said: “The COVID-19 pandemic has brought to the forefront of public consciousness the real need for new ways to control the spread of airborne respiratory pathogens. In crowded spaces, from offices to large indoor venues, shopping malls, and on public transport, there is an incredibly high potential for transmission of COVID-19 and other viruses such as flu. Most ventilation systems recycle air through the system, and the filters currently being used in these systems are not normally designed to prevent the spread of pathogens, only to block air particles. This means filters can actually act as a potential reservoir for harmful pathogens. We are excited that we have been able to develop a filter treatment which can kill bacteria, fungi and viruses — including SARS-CoV-2 — in seconds. This addresses a global un-met need and could help clean the air in enclosed spaces, helping to prevent the spread of respiratory disease.”
Dr de Cogan said that, while there have been other novel filters to ‘purify air’ — from high-efficiency particulate air filters used in aerospace cabins, to UV light, and silver nanoparticles added to filter mesh — these have fallen short as they either lack energy efficiency or speed in effectiveness and are not ideal for the majority of existing heating, ventilation and air conditioning systems which would require significant infrastructure upgrades to use them.
Dr de Cogan adds: “In comparison, the technology we have developed can be applied to existing filters and can be used in existing heating, ventilation and air conditioning systems with no need for the cost or hassle of any modifications. This level of compatibility with existing systems removes many of the barriers encountered when new technologies are brought onto the market.”
NitroPep Ltd is now further developing the filters to deliver them as a product on the market. The new technology is the latest stage of Dr de Cogan’s ongoing research creating patented antimicrobial technologies, which has included the development of a coating for surfaces called NitroPep that is also effective against SARS-CoV-2.
The latest study comes after previous research carried out globally has found that the risk of developing COVID-19 increases with greater public transport use, while other former studies have shown higher rates of flu-like illnesses in people travelling on London’s underground, as well as a 6-fold increase in respiratory infection in people using a tram or bus.
The new research, published today (9 March 2022) in Scientific Reports, was funded by the Wellcome Trust, Medical Research Council, Engineering and Physical Sciences Research Council, the Medical Research Foundation, and Engineering X Pandemic Preparedness, run by the Royal Academy of Engineering. It was carried out in collaboration with NitroPep Ltd, Pullman AC Ltd, and the University of Nottingham.

An analysis of nearly 600,000 adults in the U.S. found that those diagnosed with bipolar disorder, schizophrenia or schizoaffective disorder may have a higher risk of cardiovascular disease at younger ages compared to adults not diagnosed with one of those serious mental illnesses, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed Journal of the American Heart Association.
“Previous research has indicated that people diagnosed with a serious mental illness die 10-20 years earlier than the general population, and their leading cause of death is heart disease,” said study lead author Rebecca C. Rossom, M.D., M.S., a senior research investigator in behavioral health at the Center for Chronic Care Innovation at HealthPartners Institute in Minneapolis, Minnesota. “Our study focused on the contribution of cardiovascular risk factors, such as blood pressure, cholesterol, blood sugar, body mass index and smoking status, to compare overall heart disease risk for people with and without serious mental illness.”
The researchers believe this is the first study to examine estimated 30-year (lifetime) cardiovascular risk in a large sample of adult outpatients diagnosed with bipolar disorder, schizophrenia or schizoaffective disorder — three serious mental illnesses specific to this study. Many previous studies of cardiovascular risk for people with serious mental illness have included only people who were hospitalized, and they tend to have more severe mental illness and frailer health than outpatients, according to Rossom. In contrast, this study, included a large sample of non-hospitalized U.S. adults.
According to the National Institute of Mental Health, bipolar disorder (formerly called manic-depressive illness or manic depression) is a mental illness that causes unusual shifts in mood, energy, activity levels, concentration and the ability to carry out day-to-day tasks. Schizophrenia can cause hallucinations, delusions or disorganized speech. People with schizophrenia may seem like they have lost touch with reality, which can cause significant distress for the individual, their family and friends. The symptoms of schizophrenia can be persistent and disabling. Schizoaffective disorder is defined by the Diagnostic and Statistical Manual of Mental Disorders as an uninterrupted duration of illness during which there is a major mood episode (manic or depressive) in addition to meeting criteria for schizophrenia.
This analysis evaluated health data for nearly 600,000 people, ages 18-75 years, who visited a primary care clinic in Minnesota and Wisconsin between January 2016 and September 2018. Nearly 2%, or approximately 11,000 adults, had a diagnosis of serious mental illness. Of these, 70% were diagnosed with bipolar disorder, 18% with schizoaffective disorder and 12% with schizophrenia. On average, people with serious mental illness were more likely to be younger; female; self-identify as Black race, Native American, Alaskan race or of multiple races; and be insured by Medicaid or Medicare, compared to their counterparts not diagnosed with one of those three serious mental illnesses.
Prediction models providing a standardized metric were used to assess cardiovascular risk factors and predict the likelihood of a heart attack, stroke or cardiovascular death. To assess 10-year risk, the American College of Cardiology/American Heart Association’s atherosclerotic cardiovascular risk scoring tool was used for adults ages 40-75 years old. The Framingham Risk Score was used to estimate 30-year cardiovascular risk among adults ages 18-59 years old.
Researchers found: Adults in the study with one of the serious mental illnesses reviewed had an estimated 10-year cardiovascular risk level of 9.5%, compared to 8% for adults without a mental condition. The estimated 30-year risk of cardiovascular disease was significantly higher among those individuals with one of the three serious mental illnesses — 25% compared to 11% of people without a serious mental illness. The increased risk of heart disease was evident even in young adults (ages 18-34) with a serious mental illness. Within the subtypes of each of the three serious mental illnesses in this study, in analyses adjusted for age, sex, race, ethnicity and insurance coverage, people with bipolar disorder had the highest 10-year cardiovascular risk compared to those with schizophrenia or schizoaffective disorder, while people with schizoaffective disorder had the highest 30-year cardiovascular risk when compared to the other two groups. Smoking and body mass index (BMI) accounted for much of the risk factors contributing to cardiovascular disease in those with a serious mental illness: those with a serious mental illness were three times more likely to be current smokers (36%) compared to peers without serious mental illness (12%), and 50% of those with a serious mental illness met the criteria for obesity compared to 36% of people without a serious mental illness. People with a serious mental illness had double the rate of diagnosed diabetes (Type 1 or Type 2) than people without serious mental illness (14% vs. 7%, respectively). 15% of adults with a serious mental illness had high blood pressure vs. 13% of those without a serious mental illness.”Even at younger ages, people with serious mental illness had a higher risk of heart disease than their peers, which highlights the importance of addressing cardiovascular risk factors for these individuals as early as possible,” Rossom said. “Interventions to address heart disease risk for these individuals are maximally beneficial when initiated at younger ages.
“We encourage health care systems and clinicians to use the 30-year cardiovascular risk estimates for young adults with serious mental illness, as these may be used starting at age 18,” she said. “Right now, estimates of 10-year heart disease risk are used most frequently, and they cannot be applied until people are at least 40 years old, which is too late to start addressing heart disease risk in people with serious mental illness.”
Co-authors include Stephanie A. Hooker, Ph.D., M.P.H.; Patrick J. O’Connor, M.D., M.A., M.P.H.; A. Lauren Crain, Ph.D.; and JoAnn M. Sperl-Hillen, M.D. This work was funded by a Cooperative Agreement with the National Institute of Mental Health (NIMH), a division of the National Institutes of Health.

As scientists around the world seek for solutions for Alzheimer’s disease, a new study reveals that two indigenous groups in the Bolivian Amazon have among the lowest rates of dementia in the world.
An international team of researchers found among older Tsimane and Moseten people, only about 1% suffer from dementia. In contrast, 11% of people age 65 and older living in the United States have dementia, according to the Alzheimer’s Association.
“Something about the pre-industrial subsistence lifestyle appears to protect older Tsimane and Moseten from dementia,” said Margaret Gatz, the lead study author and professor of psychology, gerontology and preventive medicine at the Center for Economic and Social Research at the USC Dornsife College of Letters, Arts and Sciences.
Researchers used computed tomography (CT) brain scan images, cognitive and neurological assessments and culturally appropriate questionnaires — facilitated by a local team of trained translators and Bolivian physicians — to diagnose dementia and cognitive impairment among the Tsimane and Moseten.
The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, found only five cases of dementia among 435 Tsimane people and just one case among 169 Moseten age 60 and over.
In the same over-60 groups, the research team diagnosed about 8% of Tsimane and 10% of Moseten with mild cognitive impairment (MCI), which is typically marked by early stage memory loss or decline of other cognitive ability, such as language or spatial perception. The study’s authors pointed out these rates are more comparable to MCI in high-income countries like the U.S.

Professor Charles Ramassamy and his postdoctoral researcher Mohamed Haddad at Institut national de la recherche scientifique (INRS), in collaboration with scientists from Université de Montréal, McGill University, and Université du Québec à Montréal (UQAM), believe that tannic acid plays a role in inhibiting three important molecular pathways involved in the SARS-CoV-2 infection. Their work was published recently in the International Journal of Molecular Sciences (IJMS).
Using a multidisciplinary approach, the teams showed that tannic acid inhibits the viral protein (RBD) of the British variant of SARS-CoV-2 from binding to its biological target, the ACE2 receptor. This receptor, which is found on the surface of many cells in the body, allows the virus to latch on and infect them. “Tannic acid binds to the RBD protein and prevents it from binding to the ACE2 receptor,” said Professor Ramassamy. He explained that in blocking the viral protein, tannic acid does not alter the physiological functions of ACE2 receptors, which have physiological functions in the body’s respiratory, cardiovascular, and renal systems, among others.
His team further investigated the effects of tannic acid on other key mechanisms involved in SARS-CoV-2 infection downstream of the RBD-ACE2 bond. The team showed that this polyphenol can inhibit the activity of the enzyme that allows the virus to enter our cells (TMPRSS2), as well as the viral enzyme responsible for replicating the virus (3CLpro).
An alternative to antivirals
The effects of tannic acid on the RBD protein and these enzymes pave the way for further research on the entire virus in contact with human cells. If the beneficial properties are similar on a larger scale, tannic acid tablets or nasal spray could be envisaged as a means for preventing or blocking SARS-CoV-2 infection.
Tannic acid is a natural polyphenol found in many beverages such as red wine or tea, but in much lower quantities. Although they contain tannins, their consumption would not have any protective effects because of their low concentration of tannic acid.
“It would be less expensive than the antivirals currently on the market, and there would be fewer side effects because of the low toxicity of tannic acid and other polyphenols. In addition, tannic acid and its physiological derivatives have anti-inflammatory and antioxidant properties, both of which are beneficial if you are infected with SARS-CoV-2,” said Professor Ramassamy.
The research builds on the teams’ previous work on two other types of polyphenols — TGG and corilagin — and their interaction with a number of SARS-CoV-2 variants. The two compounds had similar beneficial effects, but were less effective than tannic acid.
About the study
The article “Molecular Interactions of Tannic Acid with Proteins Associated with SARS-CoV-2 Infectivity,” by Mohamed Haddad, Roger Gaudreault, Gabriel Sasseville, Phuong Trang Nguyen, Hannah Wiebe, Theo G.M. van de Ven, Steve Bourgault, Normand Mousseau, and Charles Ramassamy, was published in the International Journal of Molecular Sciences on Febuary 27th 2022. The study received financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC), the Institut sur la nutrition et les aliments fonctionnels (INAF) and Fonds de recherche du Québec — Nature et technologies (FQRNT).
Story Source:
Materials provided by Institut national de la recherche scientifique – INRS. Original written by Audrey-Maude Vézina. Note: Content may be edited for style and length.

In the wake of the Great Depression, the federally sponsored Home Owners’ Loan Corporation (HOLC) drew maps of neighborhoods in U.S. cities that characterized their desirability for mortgage lending. Many neighborhoods with Black and immigrant communities received the worst grade, restricting access to federally backed loans and favorable mortgage terms. Now, researchers reporting in ACS’ Environmental Science & Technology Letters have found that these “redlined” areas have higher levels of air pollution 80 years later.
In the U.S., people of color, particularly Black and Hispanic Americans, at every income level are exposed to higher-than-average amounts of air pollution. The reasons are complex and partly rooted in historical patterns of discrimination, experts say. Beginning in the 1930s, the HOLC rated neighborhoods in U.S. cities on a four-point scale: “A” (most desirable), “B” (still desirable), “C” (definitely declining) and “D” (hazardous for mortgage appraisal; “redlined”). Historical records indicate that many neighborhoods were given the “D” characterization because they had Black and immigrant communities. This designation limited residents’ ability to build wealth through home ownership, and it also influenced later government land use decisions to place hazardous industries in or near “D” neighborhoods. Joshua Apte of the University of California, Berkeley and colleagues wanted to examine associations between historical redlining and air pollution levels in the year 2010, which had the most recent census data available at the time of the study.
The researchers focused on two key air pollutants — nitrogen dioxide (NO2; a short-lived gas emitted by traffic, industry and other sources), and fine particulate matter (PM2.5; longer-lived, tiny particles found in dust, soot, smoke and other emissions, and also formed in the atmosphere). The team compared 1930s-era HOLC maps with 2010 air pollution levels and census demographics for 202 U.S. cities that are home to 65% of the urban population. They found that pollution levels were consistently linked with HOLC grade, especially for NO2, which was 50% higher in “D” neighborhoods than in “A” ones. At the national level, air pollution disparities were larger by HOLC grade than they were by race and ethnicity. However, within each grade, racial and ethnic disparities were observed, with lower exposure levels to NO2 and PM2.5 for white people than for people of color. Overall, the authors emphasize that present-day air pollution disparities in part reflect decisions made generations ago.
The authors acknowledge funding from the U.S. Environmental Protection Agency.
Story Source:
Materials provided by American Chemical Society. Note: Content may be edited for style and length.

Amyloid beta, a protein known to build-up in the brains of Alzheimer’s patients, also helps skin cancer cells thrive when they spread to the brain, a new study finds.
Published online March 9 in Cancer Discovery, a journal of the American Association for Cancer Research, the study found that in melanoma, the deadliest form of skin cancer, cancer cells that have spread to the brain depend on amyloid beta to survive there. The study authors focused on melanoma because it spreads (metastasizes) to the brain in 40 percent of patients with advanced (Stage IV) disease, the highest rate among common cancer types.
Led by researchers from NYU Grossman School of Medicine and its Laura and Isaac Perlmutter Cancer Center, the study revealed that metastatic melanoma cells recovered from human brains and grown in tissue cultures make roughly three times as much amyloid beta as cancer cells that have spread to other parts of the body.
The research team also found that amyloid beta secreted by cancer cells ramps down immune responses that would otherwise recognize cancer cells as abnormal and attack them, much as they attack invading bacteria. The researchers theorize that amyloid beta shifts brain immune cells into a mode seen as infections fade and tissues begin to heal, enabling cancer cells to evade notice. In addition, the team showed that a treatment known to dramatically reduce amyloid beta levels, the beta secretase inhibitor LY2886721, decreased the sizeof brain melanoma metastases by about half in study mice.
“Our study reveals an unexpected role for tumor-secreted amyloid beta in promoting the survival of melanoma brain metastases, and suggest a new way to counter it,” says senior study author Eva Hernando, PhD, professor in the Department of Pathology, and assistant dean for Research Integration, at NYU Langone Health.
The current finding adds to the mystery surrounding amyloid beta, the main component of deposits found in the brains of people with Alzheimer’s disease. Despite myriad studies, its roles in normal function and Alzheimer’s disease remain controversial, even as new proposed roles emerge, says Hernando, also a member of Perlmutter Cancer Center.

More and more American school districts have dropped mask mandates in recent weeks as coronavirus cases plunged across the United States. But they remain a subject of debate among some students and their parents, and a study released on Tuesday by the Centers for Disease Control and Prevention suggested that those mandates had helped protect children and teachers from the coronavirus last fall.The study, examining public school districts in Arkansas from August to October as the Delta variant spread, found that districts with full mask requirements had 23 percent lower rates of the coronavirus among students and staff members than districts without the mandates.It was not clear whether the same would have been true once the Delta variant was overtaken by Omicron, which is more contagious and spread rapidly among children and adults alike.The C.D.C. has faced criticism from scientists in the past for overstating the benefits of school masking based on what some researchers have described as a flawed study out of Arizona. Some studies from abroad have also found that mask mandates were not associated with lower rates of the coronavirus in children.But some scientists said that the latest C.D.C. study had steered clear of the most serious methodological problems and had strengthened the evidence for masks protecting some children from the coronavirus.“It passes the smell test,” Louise-Anne McNutt, a former C.D.C. Epidemic Intelligence Service officer and an epidemiologist at the State University of New York at Albany, said of the study. “The estimates of the impact of masks are consistent with other studies that show masks have a modest, but important, reduction of SARS-CoV-2 transmission.”The study compared coronavirus case rates among 233 Arkansas districts. About a third of the districts had full mask mandates, a fifth required masks only in certain settings or situations, and half had no mask policies.It took into account staff and student vaccination rates and socioeconomic status. It also adjusted for coronavirus rates in the surrounding community — an attempt, the study’s authors said, to partly control for how much testing was happening in a given part of the state. Dr. McNutt, though, said that the study would have benefited from more details on statewide testing levels.Districts with full mask mandates had lower coronavirus rates relative to the case rates in the surrounding community than districts without the mandates, the study found. And among roughly two dozen districts that put in place mask mandates in the middle of the study period, case rates afterward dropped more than would have been expected from changes in community case rates at the same time, the study said.Partial masking policies did not show as strong an effect as full mask mandates.The study did not account for schools’ prevention efforts beyond masking, like ventilating classrooms. Jonathan Ketcham, an economist specializing in health care at Arizona State University, said that could be an “important flaw in the study itself.”Jason Abaluck, an economics professor at Yale University’s School of Management who helped lead a large trial on masking in Bangladesh, also cautioned that the schools with mask mandates could have differed from those without them in other ways, like adherence to distancing measures. He said that the study could have more closely matched nearby schools with different masking policies to study their effects.But Dr. Abaluck said the C.D.C. study was an improvement on previous research.“This study and the broader literature on masking suggests that in places where hospitalization and deaths are very high, the benefits of mask wearing in schools may be considerable,” he said.Still, he noted that masks can cause discomfort and make it harder for children to communicate. “Figuring out how severe an outbreak has to be to warrant mask mandates in schools,” he said, “requires making best guesses about the costs, which remain highly uncertain given existing evidence.”